When I was a kid, sailing around the Thames Estuary, one of the urban myths we picked up was that tropical fish were breeding in the unnaturally warm waters surrounding the outfall at Bradwell Nuclear Power Station, on the River Blackwater in Essex.

I never saw any parrot fish on the fish-monger’s slab, but now we are confronted with something more horrible, but whether it’s any less of a less of a myth I’m not sure: namely that ’50 million fish are killed every hour’ in the cooling pipes of Britain’s nuclear power stations.

That’s the claim of Oxford University associate lecturer Dr Peter Henderson who must have one hell of a calculator.